Controller for electric motors.



R. F. BAERLOOHER. CONTROLLER FOR ELEGTRIG MOTORS. 1

APPLICATION FILED FEB. a, 1910.

Patented Oct. 7, 1913.

INVENTOR ATTORNEY UNITED STATES PATENT OFFICE.

WEB! FRIEHERICHBAERLOCHER, 0F MANCHESTER, ENGLAND, ASSIGNOR T0 WEST- I INGHDU-EE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENN- SYLVANIA.

Specification of Letters Patent.

CONTROLLER non anaemic Morons. 1

Patented Oct. '7, 1913.

Application filed FebruaryB, 1919. Serial No. 541,798.

T a all whom it may concern.

Be it known that I, Ronlnrrr FRIEDERICH BAERLooI-Inr, a Swiss subject, and a resident of Manchester, England, have invented a new and useful Improvement in Controllers for 'EIectric Motors, of which the following is as ecification.

J y, invention relates to controllers for ele'ctri'c motors and it has forits object to so construct the operating mechanism of a controller that, when the controller handle is released during its movement through one portion of its range of travel, it will; automatically return to a predetermined position, whereas, in another, portion of its range of travel, the handle may be left in any desired position.

Various means may be employed for carrying out the invention and, in order that the nature of the same may be clearly un derstood, I will now proceed to describe, with reference to the accompanying drawings, one method which I have devised which has given satisfactory results in practice.

Figure 1 is a partially sectional plan view of, a controller, and Fig. 2 is a side elevation of the upper part of the con troller shown in Fig. 1.

The shaft 1 of the controller which car- ,ri'es the controller drum (not shown) is provided with the usual handle 2 and is surrounded by a helical spring 3 one end their inner ends are connected by -a roller 10. v

Rigidly attached to the shaft 1 by means of a pin 11, is acam disk 12 having a notch 13 in its periphery which is adapted to engage the aforesaid roller 10 in a certain position of the shaft. 14 is a block which is secured to the bracket 4 and has a recess 15 to permit the passage of the cam disk 12 and is provided with notches '16, as

shown.

The roller '10 is preferably divided, as

shown in Fig.2, into three portions so that,

after it has entcred'the notches 16, as hereinafter described, the middle portion ca readily rotate in contact with the cam disk, and in opposite directionsto the top and bottom portions, thus providing an easy movement.

The operation of the device is as followsz-When the controller handle 2 is re tated' in the direction of the arrow,'Fig. 1, the notch .13 in the cam disk 12 engages the roller 10, and the links 6 and 7 and 8 and 9. are moved around the controller shaft, thereby winding up the spring 3. After the shaft has been rotated through a certain range of movement, the roller 10 will be brought by the cam disk 12 into the notches 16' in the fixed part 14 and, if the shaft be further rotated, said roller will be held in those notches by the periphery 17 of the cam disk: It will be clear, therefore, that,

during the first part of the movement of the shaft, the handle, if released, will be returned by the spring 3 to its initial position by reason of the engagement of the roller 10 with the notch 13 of the cam disk, while, during the second part of the movement of the shaft, that is to say, while the roller 10. is retained in'the notches 16, the handle may be released andwill remain in any desired position,.since the shaft 1 is no longer in operative connection with the spring 3. 1

The device above described is particularlyapplicable to controllers for variable speed motors. In this case, during the first part of the movement of the shaft, the resistance in series with the motor armature is varied for the purpose of starting, it being desirable, as' is well known, not .to leave the controller in one of these positions;' while, duringthe second part of the movement of the shaft, that is, after-the roller has been engaged by the notched block, the resistance in circuit with the field of the motor is varied in order tovgive the desired variation in speed. The invention is, however, not limited to controllers for use with this particular type of motor, nor to controllers of the drum type, but may be applied to other controllers of va rious kinds which are employed with electric motors of different types.

I claim as my invention:

1. A controller-for electric motors proleased during one portion'of its range of travel, a cam carried by said movable memher for effecting a storage of power in said returning means, and a latch for cooperationwvith said cam to lockthe returning means and release said movable member therefrom at the end of said portion of the range of travel.

2. A controller for electric motors having its drum shaft provided with spring return mechanism, means carried by said shaft for storing power in said return mechanism during a portion of the range of travel of said drum shaft, and a device cooperating with said means to lock saidvreturn mechanism and release said shaft therefrom.

3. In a controller, the combination with a rotatable member, of a spring adapted to move said member to its off position, means carried by said rotatable member and detachably connected to said spring for storing power-therein during a portion of the forward range of movement of said member, and a device for detaching the spring from said means and cooperating withsai means to hold the spring in such detached relation during further forward movement of said member.

4. In a controller, the combination with a drum shaft and a spring adapted to return said shaft to its off position, of a set of links loosely supported by said shaft and connected to one end of said spring, a cam on the shaft for engaging said links'anda latch adapted to cooperate with said cam to render the spring inefiective for a portion of the range of movement of said shaft.

5. In a controller, the combination with a druin shaft and a set of links loosely mounted thereon, of a retracting spring for said links, a notched cam keyed to the shaft and engaging said linksto store power in said spring during a portion of its range of movement, and a latch for cooperating with the cam to hold the spring and links against operative movement for the remainder of said range of movement.

In testimony whereof, I have hereunto subscribed my name, .this twentieth dav of January, 1910.

ROBERT ramnaalea BAERLOCHER. 

